If this (comment below) is in reference to air cooled ceramic metal
CPI/Eimac tubes, this is not normally true with those tubes. The
ceramic rings between plate/screen/grid/filament are not BeO but are
a high quality low loss ceramic such as Al2O3, alumina. They can
safeyl be cleaned with Bon Ami, a grit blaster, or solvents which
leave no residues.
BeO ceramic is used in certain conduction cooled tubes in which the
anode is insulated through the ceramic block making intimate thermal
contact with a cooling device. The BeO warning notice, like the HV
notice, and the RF exposure notice, is included in every tube carton
for legal reasons.
Alumina is not a listed toxin which can cause lung disease as
Beryllium Oxide can. For once I wish scary rumors wouldn't keep
getting spread like this. We handle many power tubes at work for
particle factory, and follow the laws (EPA) for dealing with waste
when they are moved, scrapped, rebuilt. If they were BeO ceramics,
things would be MUCH tougher to deal with, both legally, safely, and
administratively.
john
K5PRO
At 12:04 PM -0400 8/18/03, K8GG wrote:
>The ceramics have Beryllium Oxide so be careful when scrubbing not to abrade
>them. The hazards sheet is big on the danger of dust or fumes from BeO.
>Several posts on this reflector have warned people to wash hands thoroughly
>after handling ceramic amplifier tubes. I would guess that wearing
>dishwashing gloves would be a good idea if trying to clean the tubes.
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